Control of moving craft



June 17, im. L, DE FLOREZ 2,246,203] y CONTROL 0F vMOVINGrYGlAFT Filed Aug.' 5. 1939 Patented June 17,194.1 l L UNITED STATES' PATENT oFFicE' coN'raon oF MOVING 'CRAFT Luis de Florez, New York, N. Y., assignor to.

National Aviation Research Corporation, New York, N. Y., a corporation of Delaware Application August .3, .1939, .serial No. 288,126

` 1 claim. ((1244-87) The present invention relates to control of the dlrectionof movement and attitude of moving craft generally, but more particularly aircraft.

In prior installations as typified in Luis de Florez Patent 2,162,940, June 20, 1939 and patent application Ser. 139,868 filed April 30, 1937, directional control has been effected through the medium of a sensitive rate of turn instrument operating a valve to control differential pressures in a cylinder connected to actuate rudder, ailerons, elevators or other control surfaces. some instances, so-called booster valves were interposed'in the differential pressure lines to accomplish a power amplifying eiect.

This .amplification of power for directional. and attitude control is especially desirable, and in some instances, necessary in the automatic handling'and control of large size aircraft.

One of the objects of the present invention is to obtain all necessary power amplification without having to resort to booster valves orlike amplifying equipment. This is accomplished by utilizing the kinetic energy present in the air or rocking on an axis I'I which in this illustration other medium'in which thevcraft operates, for

example, by the provision of a movable tab in the control surfaces to be governed, said tab being directly actuated by a servo motor mounted in the control element and controlled through differential pressure lines from a rate of turn instrument, which may be disposed to respond to turn about any one or more axes.

By s0 combining and arranging the parts, a relatively small light weight power cylinder, of a size which can be readily-mounted within a -rudder or other control surface and which can be Within the true spirit of the invention, all within vthe intent and scope of the following claim.

In the drawing, Fig. 1 is a'perspective and generally diagrammatic viewl illustrating the invention embodied in a form of rudder control.

Fig. `2 is an enlarged broken part sectional plan and detail view of the power and tab locking portions of the apparatus.

Inthe'present illustration, an"i airplane is indicated at 3,.having a rudder i4. e

Mounted in and forming a lpart of the surface of the rudder, there-is shown a control tab 5, journalled to rotate on the vertical axis'S.

1 designates a small power cylinder locatedwithin the rudder surfaces andcontaining a piston 8, having a projecting rod 9, connected by pivot link I0, with the horn I I,- of the rudder tab.

The cylinder is shown supported in U-'orackets I2 lattached at I3 to rods I4 connected with the rudder post I5.

At I6, a rate of turn gyroscope is indicated,

is in line or substantially in parallel with a longitudinal axis of the aircraft, The frame of this gyroscope is shown as having an arm I8 carrying a pin I9 in engagement with lever 20 on the arbor 2I of a dilerential valve element operating within`v'alve casing 22. Details of these parts are fully shown and described in the de Florez patvision of a special tab lock by which the control' tab may be secured against movementfwhen the automatic equipment is not in service, as when' the pilot may taken over f or manual control and which can be immediately released when the automatic control is vcut into service.

Otherfeatures and objects of the invention and ldetails of construction are set forth inthe following specification, illustrated in the accompanying drawing and broadly covered; .i'n the claim dening the invention.

ents above identified, so it is suiicient for the present disclosure to understand that 23, is the suction line connected with a vacuum pump,- venturi, or other suction creating, means, that 24, is the air filter providing inlet of air into the valve casing and that 25, 26, are the two diferlential pressure lines extending from opposite sides of the valve easing to opposite ends of the servomotor cylinder and according to position of the valve element, adapted to be vsubjected to equal or to varying unlike degrees of suction and, or atmospheric pressure. These `differential pressure lines are shown brought out at the stern of lthe ship and extended up through the rudder, back of the pivot post with flexible cou- The drawing illustrates 'one typical embodil ment of the invention, it being contemplated that the structure may be changed and modified plings 21, interposed where the lines cross the pivotal center.` l

'I'he differential kpressure linesv are shown as having -gjustable valve restrictions 28, and

vacuum capacity tanks 29, for governing and regulating the application o'f the control forces to bring the craft, when a deviation occurs, back on the course, without over-swinging or setting up a hunting eii'ect, as disclosed in the first de Florez patent mentioned. Also the'valve casing is shown as adjustable at 30, for 'course changing ,.purposesjand the differential pressure lines as fha'vingia rconnection 3l with a valve 32, which 35, in segment 36, on the forward edge of the not be used,

tab. For purposes of releasing this lock, a wire or cable 31, is shown extended through a curved guide 38, into the tubular rudderr post and out through a second curved guide 39, at the foot of the post into a. fixed guide 40, in the fuselage. This lock control wire may be carried up into the cockpit, control cabin or to some other convenient position. It is shown'as secured at 4| and as carrying a ring `42 which can be caught over a hook'43 to hold the lock plunger pulled out of the notch and the tab thus free for control purposes. To lock the plunger the ring need simply be released from the hook. If the plunger is let go at a time when the notch is out of line, the nose of the plunger'will simply ride the surface-ofA the segment until the tab swings back in line with the rudder surface,'which it will naturally do when control of same is relinquished.

In thecondition illustrated in Figure 1, the locking pin 33, is Withdrawn and the control tab 5, is free to b e operated by the servomotor l. Upon the start of a turn, the gyroscope will rock the movable element of control valve 22, one way or the other,'depending on the direction of turn, thus to apply different degrees of suction, or in some instances, suction through one line and atmospheric pressure at the other, through the two differential pressure lines 25, 26. Sub- .iected to such diiferential pressures, the servo` motor piston 8, will. move one way or the other, to turn the tab in a direction and to an extent necessary to enable it to swing the rudder in the direction and to the amount required to bring ',delay in initiating or completing the necessary control adjustments. The promptness of action thus attained makes the device more`sensitive in eiect, enabling the flow restricting control valves 28, for instance, tq be more fully opened up', so that the servomotor will come into action, substantially at the instant the gyro detects a change in direction or attitude.

The ship may thus be maintainedunder better control because corrections are made before deviations reach any real magnitude. With the ow restricting valves opened up the capacity tanks 29 are made more quickly responsive. In some instances, where capacity of the cylinder and connecting lines is sufficient, the tanks may The quick acting tab control may thus have this additional advantage of eliminating need for capacity tanks in the control equipment.

When desired, the automatic control can be cut out of service by either opening up the bypass valve 32, which has theeffect of shorteclrcuiting the servomotor cylinder, or 'by releasing the ring 42 lfrom the hook 43 to permit the lock pin to drop into its notch in the tab, to secure the tab in rigid locked position where it will form part of the normal rudder surface. Then, in either event, or, if both the servomotor `has been cut out of action and the tab secured in locked condition, lthe plane may be controlled by the pilot -in the usual manner. Even with the automatic to operate under positive pressure instead of under partial vacuum, as illustrated.' Only a small amount of poweris required to swing the control tab, so the pressure creating means and the connections from the same to the servomotor can be relatively light and small. The control valve can be made vlight enough to be easily operated by the rate of turn gyroscope, without retarding or impairing the sensitivity of the latter. While the control tab is capable of effecting the full .control movements of the -rudder or other control surface, in some instances, it may be uti'- lized simply in an assisting relation, for instance, as an aid in the manual piloting of a ship. Change from automatic to full manual control can be instantly effected by simply opening the ldifferential pressure bypass valve or by unhooking the ring of the pull cable to let the lock bolt drop into the securing notch in the rudder tab. The tab is then positively held and forms a continuous part of the rudder surface. To overcome possible effects of partial vacuum at the trailing edge of the tab and to render the tab more efthereof, means for effecting independent control movements of saidv control tab and-means for locking said ,control tab against such independent movements and including a segment with a center notch, a movable locking element engageable with said 'segment and in said notch, Ia spring l* thrusting said locking'eleinent toward said segment, a pull line connected with said movable locking element for drawing the same away from said segment and means 4for holding said pull 

